Effect of form and level of N fertilizers on sheath rot (Sh R) incidence and yield [India]
1986
Alagarsamy, G. | Bhaskaran, R. (Tamil Nadu Agricultural Univ., Coimbatore (India). Plant Pathology Dept.)
The effect of three forms of N fertilizer at 60, 120, and 180 kg N/ha on Sh R [sheath rot] incidence and yield of IR 20 was studied in a pot culture experiment. Ammonium sulphate, ammonium chloride, and urea were applied 50% at transplanting, 25% at tillering, and 25% at panicle initiation. Plants were artificially inoculated with Sh R by inserting a single infected rice grain between the leaf sheath enclosing the panicle and the culm of a tiller 65 d after planting. Disease incidence on 5 randomly selected tillers from each hill was recorded 30 d after inoculation. Sh R incidence was significantly lower with ammonium chloride at all the 3 N levels. At 120 kg N/ha, ammonium chloride recorded the maximum yield (11.5 g/hill) with a disease index of 35.8%.
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